1. Field of Invention
The present invention relates to sockets for electric lamp bulbs and more particularly to sockets moulded on an insulated conductor cable, and a method and apparatus for moulding the sockets on the cable.
2. Description of Prior Art
Electrical lamp sockets known to date include a socket housing having therein a metallic cylindrical cup, the side walls of which are threaded to permit the screwing of the base of an electrical light bulb therein. At the center of this cup is a central contact which is insulated from the side walls and connects to the center contact of the lamp screw base, when a light bulb is retained in the socket, so that current will flow through the filaments of the light bulb via the cylindrical side wall and the central contact.
Other type lamp sockets of this class and more particularly of the type for use to string lights on an electrical cord, for decoration purposes, utilize a cylindrical plastic body having a metal cylindrical cup therein and having contacts as mentioned hereinabove. However, these contacts are each provided with an extension pin extending through the base into transverse cavities and protruding therethrough to provide contact with a respective insulated wire positioned and retained in each of the transverse cavities. A pair of wires is separated with each wire placed over a respective cavity and by inserting a bottom cap over the base of the cylindrical body, each of the wires are forced against a respective pin which penetrates the insulating coating and provides connection for the center contact and the side wall contact. Many of these types of lamp sockets have not proved entirely satisfactory for many reasons. Some of these reasons are that it is very expensive to produce because of time consuming manual operations, and excessive number of parts utilized in its construction. Also, the casing is generally formed of a brittle plastic material and breaks easily. Still further, many of these constructions do not provide proper ventilation and cause moisture to be trapped in the socket, thereby causing short circuits and destroying the light bulbs and sometimes the socket contacts.